When the attached document is opened, modified by changing some meta-data for example and then saved again, the watermark is changed. Before, it is visible only when printed not when shown by Acrobat Reader. Afterwards, it is visible in both cases. This is with version 4.2.0 of Pdfkit.
have tested the scenario and I am able to reproduce the same problem. For the
sake of correction, I have logged it in our issue tracking system as PDFKITJAVA-33237. We will investigate this
issue in details and will keep you updated on the status of a correction.